Premium
Temperature logs in deep wells—a useful tool for past climatic reconstruction
Author(s) -
Cermak V.,
Kukkonen I.T.,
Safanda J.
Publication year - 1993
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.1993.tb00238.x
Subject(s) - borehole , geology , climate change , climatology , global warming , permafrost , physical geography , paleontology , oceanography , geography
According to the theory of heat conduction in a semi‐infinite body, temperature changes at the surface propagate into the subsurface with the amplitude attenuation and time delay that increase with depth. Temperature changes on the earth's surface, reflecting the past climatic history, can thus be evaluated by analysing the curvature they have caused in the present temperature‐depth distribution. As a rule, temperature profiles to depths of 200–300 m record surface temperature trends accurately over the last two centuries or so; deeper holes may reveal climate history farther back but with decreasing resolution. We present several synthetic temperature‐depth profiles to demonstrate the expected signature of past surface temperature changes in the subsurface, the analysis of which may help better identify the climate of the past. Examples of extracted climate recollections from holes in North America and Europe are discussed. While inconspicuous underground records may correspond to the postglacial warming 8–11 kyr ago, reasonably well‐documented borehole logging data have confirmed climate excursions in the past millenium, namely the Little Climate Optimum and the Little Ice Age. Traces of recent warming are generally common in many temperature records, evidencing the temperature rise by 1–2 K over the past 100 years.